Phycoremediation of Sewage Using Microalgae Chlorella Sp

Phycoremediation is a novel technique that uses algae to cleanup contaminated soil and water. It takes advantage of natural ability of algae to take up, accumulate, and sometimes degrade constituents that are present in their growth environment. The present work deals with the study of remediation of sewage water using Chlorella, which is an alga, isolated from Kalapatti pond, Coimbatore. The remediation study was carried out in the sewage water collected from Thudialur municipal sewage. The physicochemical and microbiological parameters like temperature, pH, turbidity, total solids (TS), total suspended solids (TSS), total dissolved solids (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen, organic carbon (OC), chloride (Cl), hardness and calcium were analysed in raw sewage as well in treated sewage. Sewage water was diluted to different concentrations as 25%, 50%, 75% and 100%. The inoculum was taken in different concentrations for the study (10%-T1), (20%-T2). The work was carried out for a period of four months and the readings were taken for every fifteen days interval throughout the study. There was a high reduction in all the physico-chemical parameters except DO. The treated sewage was observed to be clear, but there was was no significant reduction in the microbiological parameters. The use of disinfectant after separation of the algae from treated sewage will be a complete treatment. Thus, the green algae Chlorella is effective in reducing the physico-chemical parameters of the sewage. The sewage after the treatment attained the ISO permissible limit. The treated water can be used for irrigation, fisheries, etc. The algae can be reused for further remediation process.